The invention relates to an intake-tube arrangement for internal combustion engines, whereby individual intake tubes, disposed pairwise opposite one another in approximately the same plane, said tubes being of substantially the same length, extend out from the lateral walls of an intake manifold.
In a known intake tube arrangement of this design (U.S. Pat. No. 2,862,490) for a six-cylinder in-line internal combustion engine with three carburetors, the connections of each pair of individual intake tubes to the intake manifold are located coaxially opposite one another, so that a disadvantageous mutual vibrational influence takes place between the individual intake tubes located opposite one another, said influence resulting in deterioration of supply to the engine. Moreover, the individual intake tubes consist essentially of straight and diagonal sections, connected together by bends with small radii of curvature. In this design, the streams of gas or air-gas mixture are disturbed by turbulence in the individual intake tubes, so that especially advantageous torque values and hence efficiencies cannot be achieved over the entire engine speed range. Furthermore, the individual intake tubes are relatively short, resulting in additional disadvantages in torque and efficiency.
A goal of the invention is to provide an intake-tube arrangement of the type described hereinabove, wherein disadvantageous mutual influence of vibrations in individual intake tubes located opposite one another is reduced.
This goal is achieved according to the invention by virtue of the fact that the ends of each two individual intake tubes located opposite one another and extending out from the intake manifold are connected diagonally with respect to one another to the intake manifold, whereby their imaginary extensions, continuing on into the intake manifold, intersect.
The design of the intake pipe arrangement according to the invention ensures a good vibrational behavior in the individual intake tubes and hence a good torque and efficiency for the engine, because direct pressure wave transition between individual intake tubes located opposite one another is disturbed by the fact that they are disposed at angles to one another. The intake pipe arrangement according to the invention is especially suited for fuel-injected internal combustion engines of the Otto and Diesel type, but also for Otto engines fitted with carburetors.
According to particularly preferred embodiments, as also set forth in the claims, the individual intake tubes have relatively large lengths and radii of curvature, without considerably increasing the space requirements for the intake tube arrangement, whereby flow and oscillation behavior are further improved in the individual intake tubes. Certain other features set forth in the claims allow a transition from the individual intake tubes to their connections with favorable flow conditions.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.